The processing of visual information in the primate cerebral cortex is initiated in the primary visual receiving area, striate cortex, and further elaborated in surrounding extrastriate visual areas. One of these extrastriate areas, MT, is rich in neurons which respond selectively to the direction of motion of visual stimuli. It therefore seems likely that MT is involved in the animal's perception of motion and may also direct such information to other neural systems which initiate appropriate behavioral responses. We have begun to test these hypotheses by combining behavioral and single-neuron recording techniques to investigate MT in awake rhesus monkeys. We have found cells that show directional responses similar to those observed previously in anesthetized monkeys. Neuronal responses were similar when the stimulus was moved across the receptive field as the monkey fixated and when the monkey tracked a moving target and thereby moved the receptive field across a stationary stimulus. While this similarity of response indicates a lack of extraretinal influences on these cells, preliminary evidence suggests that many direction-sensitive neurons medial and anterior to MT do respond during smooth pursuit eye movements in ways which do require extraretinal input.